Has anyone seen a problem with these motors breaking valve springs? I have a motor that has 35K on it and one spring let go and the rocker dropped out. Made a hell of a lot of noise with it out I guess the valve was tapping against the piston. It is the exhaust valve 1st cylinder in the front on the passenger side. The vehicle it is in is an 2002 Explorer just a daily transportation for a friend of mine.

By the way the cam and rocker arm look fine no damage at all.

Last edited by Paul P on Fri Mar 09, 2007 9:15 pm; edited 1 time in total

dont usually see valvetrain problems like that with the 4.6. i checked for TSBs and didnt find any. my machinist couldnt provide an explanation either. maybe just a bad spring ??? i think beersngars works at a Ford dealer. maybe he could reasearch this through one of the techs._________________

I had one a few years ago with a broken spring...when I ordered new ones from Ford they were a different style, that replaced the original...if my memory is right, the originals were a 'regular' for lack of a better word spring, and the replacements were beehive like is used now, and of course I then had to order matching retainers. I still have the ford package somewhere because I wanted to keep the part numbers... hth Hanz_________________www.hanzenginehouse.com

They are the beehive type as you stated Hanz. I can't figure it either. It is a salvage motor with low miles. This is easy to verify looking at the cam lobes. They have little to no tracking on them. Must just be a bad spring. The cams on the motor I pulled looked much different with tracks from the rollers on the cam lobes 130K miles. I will replace the spring with a new one from the dealer on Monday. This is if the valve is holding with a leak test. Thanks for the input guys.

dont usually see valvetrain problems like that with the 4.6. i checked for TSBs and didnt find any. my machinist couldnt provide an explanation either. maybe just a bad spring ??? i think beersngars works at a Ford dealer. maybe he could reasearch this through one of the techs.

OH Sorry...
Talked to 2 top techs here and both have seen the problem, but no real pattern as to age or milage. Intake or Exhaust again no pattern. Also neither know of a redesinged spring. Sorry for the delay in response.

It was a conical spring that failed by the way. Must have been worse with out them.
I do have a used core 4.6 motor for sale that is in very good shape._________________2001 Focus 2.0 Zetec
stock cams, bolt-ons and tune
15.63@87 MPH 1/4mi

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